Motor vehicle transmission



May 11, 1937. B. D. WOOLLEY MOTOR VEHICLE TRANSMISSION Filed Sept. 16,1935 l atented May 11, 193'? UNITED STATES PATENT OFFICE MOTOR VEHICLETRANSMISSION Bruce D. Wool Icy, Johnstown, Ohio Application September16, 1935, Serial No. 40,663'

Claims.

This invention relates to motor vehicle power transmissions and isparticularly directed to that type of transmission in which the drivingratio changes automatically in accordance with the demands placed uponthe vehicle to which it is applied.

The transmission forming the subject matter of the present invention isquite similar in operating principles to the transmission shown in in myco-pending application, Serial No. 25,286 of which this application is acontinuation-in-part.

The primary object of this invention is the provision of a selectivegear transmission which will utilize the resistance offered by theweight of the vehicle to be moved together with the friction developedto change the driving ratio to deliver more or less power as occasiondemands.

It is also an object of the invention to employ one or more sleevesmovable longitudinally of certain shafts to cause the engagement anddisengagement of clutches for connecting the driving gears to theshafts, or the shafts to one another.

It is a further object of the invention to provide driving means betweenthe shafts and gears which will permit relative movement therebetween sothat the gears may be maintained constantly in mesh to avoid clash andother disagreeable noise.

p0 A still further object of the present invention resides in theprovision of an automatically actuated over-drive gearing which may beemployed in the automatic transmission shown or may be applied to themanually operated transmissions forming a part of the regular equipmentof standard cars now being produced.

Further objects will be apparent from the following description taken inconnection with the drawing forming a part of this specification and 4in which is shown the preferred embodiment of the present invention.

In the drawing:

Fig. 1 is a vertical longitudinal sectional view taken through atransmission constructed in accordance with the present invention;

Fig. 2 is a similar view illustrating a manually operated transmission,employed on present standard makes of cars, equipped with the automaticover-drive gearing which forms a part of 5c the transmission shown inFig. 1;

Fig. 3 is a transverse sectional view through one of the couplingsleeves or clutches employed, the plane of the section being indicatedby the line IIIIII of Fig. l;

Fig. 4 is also a transverse section taken through a flexible drivingmember arranged between certain of the gears and their cooperatingshafts,- the plane of this section being indicated by the line IV--IVofFig. 1.

Fig. 5 is a detail transverse sectional view through a clutch used inthe transmission.

Referring more particularly to the drawing, the numeral I designates thetransmission housing which may be formed from cast iron in the usualmanner. The front and rear walls 2 and 3 of the housing are providedwith upper and lower sets of longitudinally aligned openings 4 and 5.Intermediate of the length of the housing, a pair of transverse webs 6are provided and these are also formed with openings 1 aligned with theupper set of openings 4. The upper set of openings 4 receiveanti-friction bearings 3 and the openings 1 in the webs 6 receive sleevebearings 9 for the rotatable reception of shaft sections III, II and H2.The shaft section Ill is connected at its forward end with the drivenmember of the automobile clutch (not shown) while the section i2 leadsto the drive shaft (not shown) of the vehicle. The lower set of openingsreceive the counter shaft l3 which provides an I axle for the rotatablesupport of idler gears employed in the transmission.

The shaft section II is provided with a sleeve M in the side wall ofwhich is formed a plurality of angular slots I5. ried by the shaftsection project into the slots l5 and lock the sleeve I4 thereto butpermit of a limited amount of rotative and longitudinal movementtherebetween. A gear member I! is rigidly secured to the sleeve l4 andmoves therewith.

The gear I! meshes with an idler gear 18 carried by a sleeve [9 on thecounter shaft I3. Internally the idler gear I8 is provided with aplurality of chambers 20 which include cam surfaces 2l. Each of thechambers 20 receives a hardened steel roller 22 which forms theconnecting element between the idler gear and the sleeve. This type ofconnection will permit the gear to rotate the shaft or sleeve in aforward direction but will not permit the sleeve to rotate the gear inthis direction. A connection of this type is commonly termed anover-running clutch.

The shaft section I2 is provided with a gear member 23 arranged torotate therewith through the use of splines 24 which permit the gear 23to be moved longitudinally of the shaft to engage or disengage acomplemental gear 25 also carried by the sleeve 19. When the gears 23and 25 are in engagement, rotation of the shaft section ii Pins l6 andMia rigidly car- 5 ell) will be transmitted to the shaft section i2through the gears Il i8, 23 and 25 but the latter shaft will rotate at amuch slower speed than the former.

To rotate the shaft section 2 at a faster rate but still at a speed lessthan that of section H, the sleeve 14 rotatably carries a gear member 26of a size larger than the member H. A coil spring 2?, arranged betweenthe gear 28 and a collar 28 rigidly secured to the shaft ll by the pin56a, exerts a pressure on the gear 26 to move it toward the gear ll. Thelatter gear carries a plurality of clutch dogs 29 which fit into anannular recess 38 formed in the side of the gear 26. As shown in Fig. 5,the lower ends of the dogs 29 are positioned for rocking movement withinrecesses Ila provided in the hub of the member ll. The side walls of therecesses force the dogs 29 to rotate with the member I! and when thegears El and 26 are moved toward one another, the dogs 29 become wedgedbetween the inner surface of the annular recess 30 and the bottom of therecesses Ha uniting the two mem bers for rotation together. A heavy coilspring 3! arranged between the gear i? and one of the ribs E moves thegear I! toward the gear 26 to cause the clutch dogs to establish adriving connection between the sleeve is and the gear 26. An idler gear32, also provided with an overrunning clutch as is the gear !8, mesheswith the gear 2% and transmits power therefrom to the sleeve 59, thegears 25 and 23 and the shaft it. As the gears 2E and 32 diifer in sizefrom the gears 8'5 and i8 with the gear 26 larger than. the gear ii, theshaft section l2 will rotatefaster than in the set-up previouslydescribed.

To provide for the same speed of rotation in. the shafts ii and i2, theyare coupled together by the clutch member 33. This clutch includes: ahub 34 rigidly carried by the shaft i2, a plurality of clutch dogs 29and a head 35 formed on the sleeve M and in the end of which is formedan annular recess 36. The recess 36 and. the recess 30 in gear 2% may beprovided with. a clutch lining, if necessary, to make the drivingengagement more positive. The heavy coil spring 3! moves the sleevetogether with the gears l7 and 2E and the head 35 toward the hub itcausing the dogs 29 to be wedged between the hub 35 and head 35 to forma driving connection. The engagement of this clutch takes place afterthe gear 26 has been connected with the sleeve M by its clutch,continued movement of the sleeve being possible because of the provi--sion of the coil spring 27. The spring 2'! ofiers sufiicient resistanceto the longitudinal movement of the gear 26 to permit the clutch dogs toconnect it with the gear 5 but will permit them both to move a limiteddistance after their connection. This limited amount of movementisenough to cause the actuation of the clutch. 33. When the clutch 33 isin operation, the shafts H and i2 rotate as one establishing a directdrive from the shaft ii to the rear wheels. When this direct drive isestablished, the over-- running clutches arranged between the gears iBand 32 and the sleeve l9 permit these three elements to rotate atdifferent speeds.

The hub of the gear 25 is provided with a gear" 3'2 arranged to meshwith a second gear 38 carried on a stub shaft mounted to one side of theshaft !3. The gear 23 when moved forward to the extreme end of itstravel will mesh with the gear 38 and the shaft l2 will rotate in areverse direction when the shaft l l is rotated.

Ordinarily, the shaft sections 1 3 and ii ro tate in unison because ofthe over-running clutch 39 which connects them together. The clutch 39includes a thimble 40 connected. to a sleeve ii, provided on the shaft[8, by a plurality of splines 42 which establish a positive rotatingdrive but permit relative longitudinal movement therebetween. Thethimble 40 is formed with internal chambers 43 having cam surfaces 6dand containing rollers :5 which are gripped between the cam surfaces andthe shaft H to establish a driving connection therebetween. When thethimble is rotated by the shaft id, the shaft ll will rotate therewithbecause of the clutch. However, the shaft Il may rotate at a greaterspeed than the shaft ill without rotating the thimble 4B.

The sleeve 4?, similar to the sleeve l is formed with an angular slot 46which receives 1 pin l'l' carried by the shaft H]. A spring between theend of the sleeve All andthe bearing 8 forces the sleeve toward thethimble Loosely carried by the sleeve is a large gear 39 which mesheswith a pinion 58 formed on sleeve l9.

Arranged between the gear 49 and a hub provided on the sleeve 4! is aplurality of clutch dogs 28 which, when the sleeve is moved in re--sponse to the force of the spring 48, connects them together and causesthem to rotate as one. When this occurs, the gear 49 will rotate thepinion 59 which, being a part of the sleeve IE, will cause the gear 25to rotate and in turn r0- tate the gear 23 and the shaft l2 at agreaterrate of speed than the shaft ill. This arrangement may be termedan over-drive because the shaft being driven rotates faster than theshaft doing the driving.

In the operation of the device, when the transmission is at rest, all ofthe clutches are in engagement in response to the forces of the springs21, 3! and 48. When power is applied to shaft iii, the gear 49 tends torotate the pinion to drive the vehicle but the resistance developed byfriction and the dead load holds the gear 69 stationary. The pin 11turns with the shaft and due to the angularity of the slot &6, thesleeve 4-! is drawn against the action of the spring :3 dc-clutching thegear 39 from the sleeve.

The connection between the shafts l8 and H causes the shaft ii to rotateand the sleeve i l tends to rotate therewith but, due to the re-.sistance offered by the shaft it through the clutch 33, is heldstationary and pins i5 and Ida working in slots move the sleeve againstspring 3!, de-clutching shaft 92 from shaft ii. Continued movement ofshaft H causes sleeve 54 to move against spring 3! still moredisengaging gear 26 from the sleeve M. As shaft ll continues to rotate,sleeve M must rotate for as the pins l6 and its reach the ends of theslots and since gear if is rigidly carried by the sleeve, it -willrotate positively therewith, transmitting power to the driving wheels ofthe vehicle. 'When the mechanism is in this position, the transmissionis said to be in first or low gear and maximum power is transmitted.

As the vehicle gets into motion and the requirement for power lessens,spring 3! will exert itself and move the sleeve sufficiently to causegear '25 to be engaged and the speed of the vehicle increased. Thetransmission is then said to be in second gear. The additional speedfurther lessens the requirement for power and the spring 3| will movethe sleeve still more until the clutch engages and establishes a directdrive and the transmission is then in third or high gear.

When the vehicle is moving rapidly, the requirement for power is not asgreat because the momentum helps to overcome resistance developed byfriction. The spring 48 then moves sleeve all causing gear 49 to beconnected by its clutches to the sleeve. This establishes the overdrivewhich will operate only when the vehicle is moving at a high rate ofspeed and the power requirement is at a minimum. The spring 48 is madeconsiderably weaker than the spring 3| so that the over-drive gear willonly engage with the sleeve when the vehicle has attained a high speedand will be the first to be out out when the speed is decreased.

In the form shown in Fig. 2, the over-drive mechanism employed in theautomatic transmission is installed in a standard manually shiftabletransmission. This form includes the longitudinally aligned shaftsections lilo, lid and l2a which correspond to the sections I0, I l andI2 in the automatic transmission. The shaft IEla carries a springpressed sleeve M and a thimble MI splined thereto as in the preferredform. Between the thimble ill and the forward end of the shaft sectionHa is arranged an over-running clutch, similar to clutch 39, which willpermit the shaft section Ila to rotate at higher speed than the sectionlea but will not permit it to rotate at a slower speed. When theover-drive is not operating, the power is transmitted from shaft Ilia toshaft Ma and the standard transmission.

The standard transmission depicted includes the aligned shaft sections Ila and Illa. The section iia has rigidly secured thereto a gear 5! withclutch teeth adjacent one end. The section Ila is provided with spiralkeys on which is splined a gear 55. This gear is manually shiftablelongitudinally of the shaft section on which it is mounted. A secondgear 56 is rotatably mounted on the shaft section I211 in advance of thegear 54. The gear 56 is also formed with clutch teeth adjacent one endas is the gear 5I.

Slidably keyed to the shaft I20. between the gears 5i and 55 is a clutchmember 55 provided at each end with internal clutch teeth adapted toreceive the clutch teeth on the gears 5| and 56. The clutch member 55 isalso manually shiftable to lock either the gear 5| or 56 to the shaftI2a. Below the shaft sections I la and I2a, the transmission is providedwith a counter shaft on which is rotatably supported a sleeve formedwith a plurality of various sized gears. The largest gear 52 is arrangedto constantly mesh with the gear 5| carried by the shaft section Ila.The next size gear 5'! is positioned in mesh with the gear 56 which isrotatable on the section I2a. The next smaller gear 53 is arranged to beengaged by the gear 54 when the latter is moved to its foremost positionon the shaft I2a. When these two gears are in engagement, power istransmitted from shaft Ha through gears 5I, 52, 53 and 54 to shaft lZa.Due to the particular size of the gears, this driving ratio is low.

When the gear 54 is moved rearwardly to a position between the gear 53and an idler mounted to one side of the counter shaft, the driving connection between the shafts i la and I 2a is broken and the transmissionis in neutral. When the clutch member 55 is moved to couple the gear 53to the shaft IZa, power is then transmitted through gears 5i, 5'! and 56and the driving ratio is slightly raised.

To further increase the driving ratio, the

clutch member 55 is moved forward to couple gear 5! to shaft I2a atwhich time this latter shaft and the section I Ia will rotate in unisonand a direct drive from engine to drive shaft is established.

Arranged about the countershaft in advance of the gear equipped sleeveis a second sleeve which is keyed to the first sleeve and has a gear 55aformed therewith. The gear 56a meshes with another gear 39a rotatablycarried by the sleeve ti. A clutch of' the type used to couple the gearsto their sleeves in the preferred form of the invention is employed tounite the gear 59a with the sleeve 4i.

When: the vehicle reaches a speed previously determined, the powerrequirement is lessened sufiiciently to permit the spring 48 to overcomethe end thrust of the sleeve M generated by the resistance between thegears tea and the. This will cause the gear $9 to be clutched to thesleeve and power will then pass through gear 69, pinion 5%, gears 52 andSI to shaft 52a. Shaft Ha will then rotate with gear 5i at a greaterrate of speed than shaft El a; this difference in rate of rotation beingmade possible by the employment of the over-running clutch between thethimble and shaft Ila.

When the automatic transmission forming the subject of the presentinvention is employed, it

will be necessary to provide means in connection 3:.

with the vehicle clutch to hold it disengaged when it is desired toleave the car with the engine running.

While I have shown and described what I believe to be the preferred formof my invention, nevertheless, I wish it to be understood that numerouschanges may be made in the construction of the various parts of thetransmission without departing from the spirit and scope of theinvention as has been set forth in the following claims.

What is claimed is:

l. A power transmission comprising a plurality of longitudinally alignedshafts, a counter shaft extending parallel to said shafts and spacedtherefrom, a spring pressed sleeve carried by one of said shafts, a pincarried by the shaft supporting said sleeve, said pin extending into anangular slot formed in said sleeve whereby relative rotative movementbetween said sleeve and shaft will cause limited longitudinal movementtherebetween, gear members carried by said sleeve and shafts, clutchmeans coupling one of said gears for rotation with the sleeve supportingit, said clutch being actuated by longitudinal movement of said sleevein response to spring pressure, I

and complemental gears carried by said counter shaft in meshingrelationship with the gear members carried by said sleeve and shafts.

2. A power transmission comprising a pair of longitudinally alignedshafts, a spring pressed sleeve member carried by one of said shafts,said sleeve member being movable a limited distance both longitudinallyand rotatively with respect to said shaft, cam means between said sleeveand its shaft for moving the former against the action of the spring,clutch means between said sleeve and the second shaft, said clutch beingactive when said sleeve moves in response to said spring, a gear memberrotatively carried by said sleeve, clutch means actuated by movement ofsaid sleeve in response to pressure by said spring for securing saidgear to said sleeve, said second clutch being operated slightly inadvance of said first clutch, means for yieldably holding said gearagainst longitudinal movement by said spring, a

counter shaft extending parallel to said first mentioned shafts andlaterally spaced therefrom, a gear carried by said second shaft, andgears rotatively carried by said counter shaft and meshing with thegears on said sleeve and shaft.

3. In a power transmission of the type including a driving shaft, adriven shaft, a countershaft and complemental gears carried by saidshafts,- in combination with a second driving shaft united with saidfirst driving shaft by a one-way clutch, a sleeve carried by said seconddriving shaft for limited rotative and longitudinal movement withrespect thereto, spring means moving said sleeve in one direction onsaid shaft, cam means between said sleeve and its supporting shaft formoving said sleeve against the action of said spring, a co-acting gearrotatably carried by said sleeve, clutch means operated by thelongitudinal movement of said sleeve in response to said spring foruniting said co-acting gear and sleeve, and a complemental gear carriedby said countershaft and meshing with the gear on said sleeve.

4. An automatic change speed transmission comprising a driving shaft, anintermediate shaft, a driven shaft, a countershaft, a sleeve mounted forlimited longitudinal movement on said intermediate shaft, spring meansfor moving said sleeve toward said driven shaft, cam means arrangedbetween said sleeve and its supporting shaft for moving said sleeve inopposition to said spring, clutch means operated by the longitudinalmovement of said sleeve in response to said spring for uniting saidsleeve and said driven shaft, a gear rigidly carried by said sleeve, asecond gear rotatably carried by said sleeve, a second clutch operatedby the initial longitudinal movement of said sleeve in response to saidspring for uniting said sleeve and said second gear, a pair of gearsrotatably mounted on said countershaft in meshing engagement with thegears on said sleeve, one-way clutches between said pair of gears andsaid countershaft, a gear rotatable with the driven shaft, acomplemental gear secured on said countershaft in meshing relationshipwith the gear on said driven shaft, a third one-way clutch uniting saiddriving shaft and said intermediate shaft, a second sleevelongitudinally movable on said driving shaft, a spring acting to movesaid second sleeve, cam means between said second sleeve and itssupporting shaft for moving said sleeve in opposition to said spring, agear rotatably supported by said second sleeve, clutch means operated bythe longitudinal movement of said second sleeve in response to saidspring for uniting said second sleeve with the gear supportedthereby,and a pinion rigidly carried by said countershaft in meshing engagementwith the gear on said second sleeve.

5. In a power transmission having a drive shaft and a counter shaft, anangularly slotted sleeve mounted on one of said shafts for limitedrotative and longitudinal movement relative thereto, spring means movingsaid sleeve in one in response to pressure by said spring, and a ycomplemental gear carried by said counter shaft in meshing relationshipwith the first-mentioned gear.

BRUCE D. WOOLLEY.

